Photoredox and Vanadate Cocatalyzed Hydrolysis of Aryl Ethers at Ambient Temperature

Cleavageof aryl ether C-O bonds is significantfor bothbiomass utilization and synthetic chemistry. However, a general methodwith high selectivity and atom economy, under mild reaction conditions,is unavailable. Herein, we describe photoredox and vanadate cocatalyzedhydrolysis of aryl ethers to cleave C-O bonds at ambient temperaturevia a cation radical-accelerated nucleophilic aromatic substitutionenabled by a "hydroxyl shuttle" pathway. Specifically,a vanadate derived from V2O5 in situ hydrolysisserves as a nucleophile to an aryl ether radical cation due to noncovalentinteractions. A favorable V & BULL;& BULL;& BULL;O interaction in thecorresponding Meisenheimer-like intermediate facilitates ether C-Obond cleavage. In situ hydrolysis of the resulting phenyl vanadateenables nucleophilic vanadate catalyst recycling. Cooperation of theseprocesses complete the transfer of hydroxyl groups from water to areneradical cations. This method offers a preferred option for C-Obond cleavage and demonstrates potential application to lignin degradation.